September Weather in , Slovenia

Last updated: August 27, 2025

September in Slovenia showcases a vibrant transition from summer warmth to the cooler embrace of autumn. With maximum temperatures reaching a pleasant 33°C (91°F), the month offers an average of 17°C (62°F), while evenings can dip to a refreshing 3°C (38°F). Though 125 mm (4.9 in) of precipitation graces the landscape on approximately 11 days, the 65% humidity adds a touch of moisture to the air, enhancing the rich colors of the blooming foliage. This month is an ideal time to experience Slovenia's natural beauty and cultural vibrancy as it prepares for the seasonal shift.

September Temperature in

As summer transitions into autumn, September in Slovenia showcases a delightful shift in temperatures, offering a perfect balance for outdoor enthusiasts. With a minimum of 3°C (38°F) and an inviting average of 17°C (62°F), the air begins to cool while still retaining the warmth from the summer months. Max temperatures reach up to 33°C (91°F), allowing for lingering days reminiscent of summer. This month marks a gradual decline in warmth compared to the sweltering highs of August, yet still invites visitors and locals alike to enjoy the beautiful landscapes under a softening sun. Ideal for hiking and exploring the stunning nature, September presents a lovely window for experiencing the charm of Slovenia before the colder months set in.

September Weather in : Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in , showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In , September typically has an average temperature of {2}°C ({3}°F), with highs reaching up to {4}°C ({5}°F) and lows dropping to around {6}°C ({7}°F).
JanFebMarAprMayJunJulAugSepOctNovDec333944536070727262544437
Data source: Temperature data for generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

September Precipitation in

In September, Slovenia experiences a notable peak in precipitation, with 125 mm (4.9 in) of rainfall recorded over 11 days. This surge signifies a transition from the warm summer months to the cooler autumn season, as September often acts as a bridge for changing weather patterns. Notably, this rainfall is among the highest of the year, following May, which enjoys even more precipitation at 129 mm. As the days start to shorten and temperatures begin to dip, this increase in moisture prepares the landscape for the vibrant fall colors and the onset of winter. Overall, September's substantial rainfall not only enhances the lushness of Slovenia's scenery but also marks a significant shift in the climatic rhythm of the region.

September Precipitation Trends in

The chart displays monthly precipitation patterns in , with values for each month alongside September’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how September’s conditions compare to those of other months. In , September typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec31534660129859588125668167
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
Choose your preferred precipitation unit

September Humidity in

As summer fades into autumn, September in Slovenia experiences a noticeable shift in humidity, averaging around 65%. This marks a slight increase from the drier summer months, where humidity dipped to 60% in August. The trend throughout the year showcases a gradual decline in humidity from the damp chill of winter, peaking at an impressive 90% in January, before reaching its annual low in July. However, as the season transitions, humidity levels begin to rise once again, hinting at the approaching wetness of fall, which can see percentages soaring back up to 84% by October. This dynamic shift underlines the typical Slovene climate, where the crispness of autumn brings a refreshing yet slightly more humid air.

September Average Humidity in

This chart illustrates the average monthly humidity levels in , with September’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In September, average humidity in is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec90%84%78%73%71%73%70%60%65%84%89%89%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in

In September, Slovenia experiences a noticeable shift in its UV Index, dropping to 6, categorizing it as high with a burn time of 25 minutes. This trend marks a gradual decline from the peak summer months of July and August, where UV levels reached a high of 9. As autumn approaches, the sun's intensity lessens compared to the peak summer heat, urging individuals to remain vigilant, especially during midday hours. With a moderate exposure, September is a perfect time to enjoy outdoor activities while being mindful of sun protection. For a detailed overview of UV index trends throughout the year, check out this useful resource: UV Index.

Maximum UV Index Levels in for September

The chart shows the monthly maximum UV Index (UVI) for in September, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In September, the maximum UV index in typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec235689986432
Data source: September UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

September Sunshine in

September in Slovenia is a delightful transition into autumn, showcasing a robust 322 hours of sunshine. This vibrant month, with its blend of warm days and crisp air, signifies a slight dip from the summer peak of 423 hours in July and 389 hours in August. However, it still offers a generous amount of sunlight compared to the colder months ahead, such as 285 hours in October and 201 hours in November. As the days grow shorter, the sunny rays of September invite outdoor adventures amidst breathtaking landscapes, making it an ideal time to enjoy Slovenia's natural beauty before the chill sets in.

Monthly Sunshine Duration in : September Highlighted

The September sunshine duration represents the total number of hours experiences direct sunlight during the month of September, excluding cloudy or obstructed periods. This chart compares the sunshine duration of September with the other months of the year.
JanFebMarAprMayJunJulAugSepOctNovDec163h222h299h332h366h403h423h389h322h285h201h201h
Data source: September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in During September

September in Slovenia presents a promising chance of sunny weather, with a 52% likelihood of sunshine gracing the skies. This marks a slight uptick compared to the summer months, where the chances hovered between 45% and 55%. The transition into autumn, while generally associated with diminishing daylight, still retains some of the vibrancy of summer. Notably, as we look back through the year, January starts off with the lowest probability of sun at only 28%, gradually rising through the months, peaking in March and June at 55%. Overall, September continues this positive trend, making it a delightful time to explore Slovenia's scenic landscapes under the warmth of the sun before the chill of autumn sets in.

Percentage of Sunny Days in September in

The chart illustrates the percentage of sunny days in throughout the year, with September highlighted. It highlights the variation in sunshine across each month and provides an overview of the typical frequency of sunny days, offering insights into how often experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec28%50%55%40%38%55%48%45%52%42%26%32%
Data source: September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in in September

As summer gracefully transitions into autumn, September in Slovenia offers a delightful 12 hours of daylight, marking a gradual decline from the sun-drenched days of July and August, which boast 15 hours of light. This month serves as a bridge between the vibrant long days of summer and the shorter, cozier days of fall. Following the peak daylight duration in June, visitors can observe that as nature begins to prepare for the cooler months ahead, daylight starts to wane. The steady decrease in daylight hours that commenced in late summer highlights the seasonal rhythm, inviting both locals and travelers to savor the perfect balance of warmth and evening sunsets before the days shrink further into October's 10 hours of light.

Average Daylight Hours in for September

The chart illustrates the variation in daylight duration in throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec9h 2m10h 19m11h 56m13h 35m15h15h 43m15h 20m14h 5m12h 29m10h 51m9h 24m8h 38m
Data source: daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in

As September winds blow through Slovenia, they offer a gentle transition from the warmer summer months. With an average wind speed of 1.8 m/s (4 mph), this is one of the calmer periods of the year, mirroring the breezy delight of August. The lingering warmth of summer seems to hold on as the winds ease, creating a serene atmosphere. Interestingly, September's wind speed is the lowest recorded for the entire year, contrasting with the brisker months of October and November, which see an increase to 2.5 m/s (6 mph) and 1.9 m/s (4 mph) respectively. This subtle dip in wind invites a sense of relaxation, perfect for enjoying the vibrant autumn scenery that Slovenia has to offer.

Average September Wind Speed in

The chart displays monthly wind speed patterns in , with values for each month shown alongside September's data, which is highlighted for easy comparison. It illustrates the average wind speed, offering insights into how September's wind conditions compare to the rest of the year.
JanFebMarAprMayJunJulAugSepOctNovDec2.52.62.52.82.72.12.41.81.8 m/s2.51.92.1
Data source: September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Compares to Other Months

Weather in varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in , focusing on differences in temperature, rainfall, humidity, and UV levels.

In September, the weather is characterized by a wide temperature range, with minimums around 3°C (38°F) and maximums reaching as high as 33°C (91°F), resulting in an average of 17°C (62°F). The month sees considerable precipitation, with 125 mm (4.9 in) falling over approximately 11 days, and humidity levels hovering around 65%. In stark contrast, January brings much colder temperatures, with a minimum of -15°C (5°F) and a maximum of only 14°C (58°F), averaging just 1°C (34°F). Precipitation is significantly lower at 31 mm (1.2 in) across 6 days, but the humidity rises to a notable 90%. For more details, you can check out the weather in January.

September and February present contrasting weather patterns that highlight the shift in seasons. In September, temperatures can range from a chilly 3°C (38°F) to a warm 33°C (91°F), with an average of 17°C (62°F). This month typically sees about 125 mm (4.9 in) of precipitation over 11 days and a moderate humidity level of 65%. In contrast, February is much colder, with temperatures fluctuating between a minimum of -12°C (11°F) and a maximum of 20°C (68°F), averaging just 4°C (39°F). Despite its lower total precipitation of 53 mm (2.1 in) over 8 days, February boasts a higher humidity level of 84%. For more details on February weather, you can visit weather in February.

September and March present quite a contrast in weather patterns. In September, temperatures range from a minimum of 3°C (38°F) to a maximum of 33°C (91°F), with an average of 17°C (62°F). This month also experiences substantial rainfall, with about 125 mm (4.9 in) over 11 days and a humidity level of 65%. In contrast, March is significantly colder, featuring temperatures from a low of -18°C (-1°F) to a high of 23°C (73°F), with an average of just 7°C (44°F). Precipitation in March is lower, at 46 mm (1.8 in) spread over 9 days, but humidity is higher at 78%. For more detailed information, you can check the weather in March.

In comparing the weather of September and April, notable differences emerge in both temperature and precipitation patterns. September boasts a wider range of temperatures, with minimums around 3°C (38°F), an average of 17°C (62°F), and maximums reaching up to 33°C (91°F). This month is also characterized by relatively higher precipitation levels, totaling 125 mm (4.9 in) over 11 days, resulting in a humidity level of 65%.

In contrast, April experiences cooler temperatures, with minimums dipping to -5°C (24°F), an average of 12°C (53°F), and maximums peaking at 28°C (82°F). Precipitation is significantly lower in April, totaling 60 mm (2.4 in) over 10 days, alongside a higher humidity level of 73%. For a closer look at the specifics of this month's climate, you can check out the weather in April. Overall, September tends to be warmer and wetter, while April is cooler and relatively drier.

In September, temperatures range from a cool 3°C (38°F) at night to a hot 33°C (91°F) during the day, with an average temperature of 17°C (62°F). The month sees moderate precipitation of 125 mm (4.9 in) spread across 11 days, leading to a humidity level of about 65%. In contrast, May experiences slightly warmer temperatures, with a minimum of 3°C (37°F), an average of 16°C (60°F), and a maximum of 32°C (89°F). The precipitation in May is a bit higher at 129 mm (5.1 in) over 17 days, contributing to a higher humidity level of 71%. For more details about the weather in May, visit weather in May.

In comparing the weather between September and June, we notice a shift towards cooler temperatures as summer wanes. September features a minimum temperature of 3°C (38°F) and averages around 17°C (62°F), with a peak of 33°C (91°F), while June starts warmer with a minimum of 7°C (45°F) and an average of 21°C (70°F), reaching a maximum of 36°C (97°F). Precipitation in September is notably higher, totaling 125 mm (4.9 in) over 11 days compared to June's 85 mm (3.3 in) over 13 days. Additionally, June has a slightly higher humidity at 73%, compared to September's 65%. For more detailed information, you can check the weather in June.

When comparing the weather in September to that of July, several notable differences emerge. September experiences a broader temperature range, with minimums dipping to 3°C (38°F) and maximums reaching up to 33°C (91°F), resulting in an average of 17°C (62°F). In contrast, July offers a warmer climate, boasting minimum temperatures of 10°C (50°F) and maximums hitting 36°C (97°F), leading to a higher average of 22°C (72°F). Precipitation is relatively close between the two months, with September receiving 125 mm (4.9 in) over 11 days, while July records slightly less at 95 mm (3.7 in) across 12 days. However, humidity levels remain slightly higher in July at 70%, compared to September’s 65%. For more detailed information about the weather in July, you can visit weather in July.

September's weather exhibits a noticeable decrease in both minimum and average temperatures compared to August. With a minimum temperature of 3°C (38°F) and an average of 17°C (62°F), September is significantly cooler than August, which ranges from a minimum of 9°C (48°F) and an average of 22°C (72°F). While August enjoys higher maximum temperatures, reaching up to 37°C (99°F), September's peak temperature is a milder 33°C (91°F). Additionally, September experiences more precipitation, totaling 125 mm (4.9 in) over 11 days, in contrast to August's 88 mm (3.5 in) within the same number of days. Humidity levels are also slightly higher in September at 65%, compared to 60% in August, further indicating a shift to a more transitional weather pattern as summer gives way to autumn. For a detailed look at weather conditions in August, visit weather in August.

September and October present a noticeable shift in weather patterns. September typically boasts a wide temperature range, with minimums dipping to 3°C (38°F) and maximums soaring to 33°C (91°F), resulting in an average temperature of 17°C (62°F). In contrast, October experiences cooler temperatures, starting with a minimum of 0°C (32°F) and an average of just 12°C (54°F), reaching a maximum of 26°C (79°F).

Precipitation also decreases from September's 125 mm (4.9 in) over 11 days to October's 66 mm (2.6 in) over 9 days. Additionally, humidity levels rise from 65% in September to a more significant 84% in October, contributing to a decidedly more autumnal feel. For more detailed information, you can check the weather in October.

September and November present contrasting weather conditions. In September, temperatures range from a minimum of 3°C (38°F) to a warm maximum of 33°C (91°F), with an average of 17°C (62°F). The month experiences significant precipitation at 125 mm (4.9 in) over roughly 11 days, accompanied by a humidity level of 65%.

In contrast, November sees much colder weather, with temperatures dipping to a minimum of -5°C (23°F) and averaging around 7°C (44°F), peaking at a milder 20°C (68°F). Precipitation decreases to 81 mm (3.2 in) over approximately 10 days, but the humidity rises sharply to 89%. For more detailed information, check out the weather in November.

September and December present contrasting weather patterns. In September, temperatures range from a mild minimum of 3°C (38°F) to a warm maximum of 33°C (91°F), with an average of 17°C (62°F). The month also experiences significant rainfall, totaling 125 mm (4.9 in) over 11 days, accompanied by a comfortable humidity level of 65%. In stark contrast, December's temperatures drop significantly, with a minimum of -7°C (20°F) and an average of just 3°C (37°F), peaking at a maximum of 17°C (63°F). Precipitation decreases to 67 mm (2.7 in) over 8 days, but humidity rises to a high of 89%. For more detailed information, check out the weather in December.

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Conclusion: What to Expect From September Weather in

As September rolls in, the weather begins to transition, offering a delightful mix of warmth and coolness. Unlike the scorching summer months, this month showcases moderately high temperatures with a refreshing average, while the night air can dip to chilly levels. Rain becomes a familiar companion, with rainy days punctuating the early onset of autumn, contributing to a noticeable increase in humidity. This unique blend of warm days and crisp nights makes September a month of change and preparation for the seasonal shift ahead, capturing the essence of autumn's approach. To learn more about the changing climate, visit Climate.